Metal-containing monoazo dyestuffs



3,468,871 METAL-(IQNTAINING MONOAZO DYESTUFF S Klaus Leverenz and Alois Gottschlich, Leverkusen, Germany, assignors to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a German corporation No Drawing. Filed Mar. 17, 1965, Ser. No. 440,629 Claims priority, application Germany, Mar. 26, 1964,

Int. Cl. C09b 29/36, 45/22 US. Cl. 260-145 20 Claims ABSTRACT OF THE DISCLOSURE Complexes of a metal such as chromium, manganese, iron, cobalt, nickel and copper with a dyestufi or a mixture of dyestufis of the formula:

nited States Patent 3,468,871 Patented Sept. 23, 1969 acid amide groups as well as further azo groupings; the

in which A is substituted or unsubstituted phenylene or I OH a no N R3 CONE-R5 in which B is a divalent residue of an enolic or phenolic coupling compound containing the OH group in a position adjacent to the azo bridge; R is sulfonamide, substituted sulfonamide, nitro, hydrogen or chloro; R is phenyl; and R is hydrogen or an acyl derivative of ammonia.

The present invention relates to novel azo dyestufis; more particularly it relates to metal complexes of monoazo dyestuffs of the formula In this formula A stands for a radical from the benzene or naphthalene series in which the substituent X is m the ortho-position relative to the azo group, X stands dyestuffs may also exhibit fiber-reactive substituents.

The novel metal-containing azo dyestuifs are obtained by the action of metal discharging agents on azo dyestuffs of the formula wherein A, R and R have the above indicated meaning, X stands in A in the ortho-position relative to the azo group and X is a complex forming substituent or a substituent which is converted to a group of this type under the metallizing conditions.

Examples of metal complex forming groups X are -OH, optionally substituted amino groups and -COOH; substituents which are converted to metal complex bonded groups under the metallizing conditions include alkoxy, chloro, acyloxy such as for instance benzenesulfonyloxy and carbalkoxy groups, hydrogen and sulfonic acid groups (converted into metal complex bound substituents by oxidative coppering in the case of the last two substituents).

Azo dyestufis of the Formula I can be prepared in known manner by coupling diazotized amines J&NH2 wherein A and X have the above specified significance and X is in the ortho-position relative to the amino group, with imidazole or its derivatives substituted at the 4- and/or S-position by alkyl, aralkyl, aryl or cycloalkyl, where the alkyl radicals may also be joined to form a closed ring, optionally with the inclusion of heteroatoms. Suitable diazo components which may be considered for application for this purpose are, for instance, derived from: 2-amino-l-hydroxy-benzene, 3 -amino -4-hydroxyl-methylb enzene, 4-chloro-2-amino-l-hydroxybenzene, 4,6-dichloro-2-amino-l-hydroxybenzene, 4- or S-nitro-Z-amino-l-hydroxybenzene, 5-nitro-3-amino-2-hydroxy-l-methylbenzene, 5-nitro-3-amino-4-hydroxy-l-methylbenzene, 4-chloro-6-nitro-2-amino-l-hydroxybenzene, 6-chloro-4-nitro-2-amino-l-hydroxybenzene, 4-chloro-5-nitro-2-amino-l-hydroxybenzene, 4,6-dinitro-2--amino-l-hydroxybenzene, 6-nitro-2-amino-4-acetylamino-l-hydroxybenzene, 3-amino-4-hydroxyacetophenone, 2-aminophenol-4-sulfonic acid, 2-aminophenol-4-sulfonic acid amide, 2-aminophenol-4-sulfonic acid methylamide, 2-aminophenol-4-sulfonic acid dimethylamide, Z-aminophenol-Lsulfonic acid anilide, (3-amino-4-hydroxyphenyl)-methyl-sulfone, (3-amino-4-hydroxyphenyl)-ethyl-sulfone, 2-aminophenol-5-sulfonic acid amide and its N-substituted derivatives,

(4-amino-3 hydroxyphenyl) ethyl-sulfone, (4-amino-3-hydroxyphenyl benzyl-sulfone, 1-amino2-hydroxynaphthalene-4-sulfonic acid, 1-amino2-hydroxy-6-nitronaphthalene-4-sulfonic acid, Z-aminobenzoic acid,

4- or -chloro-2-aminobenzoic acid,

4- or 5-nitro-2-aminoben'zoic acid, and 2-aminobenzoic acid-4- or 5-sulfonamide.

, When in the general formula of the monoazo dyestuffs X represents a substituent which is converted to an OH group or an optionally substituted amino group during the metallizing operation, the diazo components which may be applied are for instance derived from the following amines:

2chloro5-nitro-7-aminobenzene, 2-chloro-l-aminobenzene-S-sulfonic acid amide, 2-chloro-1aminobenzene-S-sulfonic acid methylamide, (4-chloro-3 aminophenyl)methyl-sulfone, (4-chloro-3-aminophenyl) ethyl-sulfone, 3-aminobenzene-sulfonic acid-( 1 and 2-aminobenzene-disulfonic acid-( 1,4).

The imidazoles employed as the coupling components may be obtained by known methods, for instance by the reaction of a-hydroxyor a-halogen-ketones with tormamide [H. Bredereck and G. Theilig, Chem. Ber. 86, 88 (1953)]. Suitable coupling components are, for instance:

imidazole,

4,5-dimethyl-imidazole,

4, S-diethyl-imidazole,

4,5 dipropyl-imidazole,

4,S-di-n-butyl-imidazole,

4,5 di-isobutyl-imidazole,

4, S-di-n-amyl-imidazole,

4,5 -'bisfi-phenyl-ethyl -imidazole,

4,5, 6,7-tetrahydrobenzimidazole,

4- (5 phenyl-S- (4) ethyl-imidazole,

4- 5' phenyl-imidazole,

4,5 diphenyl-imidazole,

4, S-bis- 2-chlorophenyl) imidazole,

4,5-bis- 4"-bromophenyl imidazole,

4,5 bis- (4-methoxyphenyl) imidazole,

4- (5 phenyl-S- (4 (4'-dimethylaminophenyl) imidazole, 4,5 bisa-furyl) -imidazole, and

4,5 bis- 5 '-bromo-2'-hydroxyphenyl imidazole.

Coupling of the starting components is carried out in an aqueous or organic-aqueous medium, preferably at pH values greater than 7. Pyridine is preferably employed as the organic solvent.

The complex forming metals employed for the process according to the invention are preferably those of atomic number 24 to 29, and in particular agents discharging copper, nickel, chromium and cobalt. Metallizing with these substances is carried out in an aqueous, organic or organic-aqueous medium. Acetone, glycol, formamide, and dimethylformamide have proved particularly suitable as organic solvents for this purpose, and they are employed by themselves, as mixtures with each other or as mixtures with Water. It is possible to prepare 1:1 or also 1:2 complexes.

Metallizing can be carried out with or without the addition of acid binding agents. Aqueous or alcoholic solutions of ammonia or alkali metal hydroxides may be mentioned as examples of acid binding agents. Mixtures of different monoazo dyestuifs of Formula I or mixtures of a monoazo dyestulf (I) of this type with another azo dyestuff which forms metal complexes may also be employed for the metallizing operation.

The dyestulf-metal complexes obtainable according to the invention are particularly suitable for dyeing natural of synthetic polyamide fiber materials such as wool, silk,

leather, synthetic superpolyamides and superpolyurethanes. Especially valuable dyeings are obtained with the dyestuiI-cobalt complex compounds. Excellent fastness properties to light, Washing, perspiration and sea Water are for instance obtained on synthetic superpolyamide fibers.

The water-insoluble dyestuff-metal complexes often possess a good solubility in organic solvents, especially in ketones and glycols and are, therefore, suitable for, e.g., the dyeing of organic liquors or lacquerson the base of spirit-soluble nitrocellulose, natural or synthetic resins, esterand ketone-soluble vinyl chloride polymerizates as they are used for the preparation of mordants' for staining wood or ball pen pastes. Furthermore, they are suitable for the dyeing of foils or spinning solutions, such as foils or spinning solution of cellulose esters or cellulose ethers, polyester resins, celluloid or polymethacrylic resins.

The parts specified in the following examples, given for the purpose of illustrating the invention, are parts by weight.

' EXAMPLE 1 A suspension of the diazo compound prepared as usual at 05 C. from 13.7 parts of Z-aminophenol-sulfonic acid- (4)-arnide, 20 parts of 30% hydrochloric acid, 5 parts of sodium nitrite and 150 parts of water is added at 05 C. to a mixture of 17 parts of 4,5-diphenylimidazole, parts of pyridine, 40 parts of 40% sodium hydroxide solution and 50 parts of ice, and stirred at O5 C. until coupling has been completed. The resultant dyestuif is precipitated by the addition of parts of 30% hydrochloric acid, filtered off with suction, washed with water and dried. It consists of an orange coloured powder and has the following composition.

6.1 parts of this dyestufi in 100 parts of formamide and 50 parts of dimethylformamide are heated at 80 C. for 4 hours With 2.2 parts of crystalline chromic chloride. whilst stirring. The reaction mixture is poured into 500 parts of water and the resultant 1:2-chromium complex precipitated by the addition of hydrochloric acid, filtered off with suction and dried. It consists of a dark powder which dyes wool and synthetic superpolyamide fibres from a weakly acidic or neutral liquor to dark green shades with good wet fastness properties.

EXAMPLE 2 3 parts of crystalline cobalt sulfate are dissolved in 35 parts of water, 30 parts of 25% ammonium hydroxide solution and 1 part of 30% hydrogen peroxide solution are added, and after stirring for one hour the mixture is added at 80 C. to a solution of 9.1 parts of the metal-free dyestuff obtained according to the process of paragraph 1 of Example 1 in parts of water and 15 parts of 40% sodium hydroxide solution. The temperature iskept at 80 C. for 15 minutes and the solution is clarified with active charcoal. The resultant cobalt complex is precipitated by the addition of acetic acid, filtered off with suction and washed with water. When dried, it consists of a dark powder which dyes wool and synthetic superpolyamide fibres from a Weakly acidic or neutral liquor uniformly to fast bluish green shades. The dyeings have good general fastness properties and fastness to light.

Similar dyestulfs are obtained when the diazo and/ or coupling component in Example 1 is replaced by the compounds listed in the following table and they are metallized by the specified method:

Color shade of complex on synthetic Coupling Type of superpoly- Diazo component component complex amide fibers Z-aminophenoM- Imidazole Go Blue grey.

sulfonic acid amide.

D 4-phenylimidazole. Co Violet.

2-aminophenol-4- 4,5-diphenyl- Go Blue green.

sulionic acid imidazole. methylamide.

Do -do. Bluish green. 2-aminophenol-5- .-do Do.

sulfonic acid amide.

Do do Cr Dark green. (a amino--hydroxydo Co Bluisli green.

phenyl)-ethylsulfone.

Do do Cr D0. 4-nitro-2-aminophenoldo Do.

6-sulfonic acid. 4nitro-Z-aminophen01 Imidazole 00 Grey.

Do 4-phenylimidazole. Go Do. 4-chloro-2-aminophenol do Go Do. -nitro-fZ-aminophenol.-. 4,5-dirnethyl- Co Blue green.

imidazole. z-aminophenol-i- 4,5-diphenyl- Go Do.

sulionic acid-B- imidazole. hydroxyethyl-amide. 6-chloro2-am.inodo C0 D0.

phenol-4-sulione acid-B-hydroxyethylamide.

EXAMPLE 3 4.3 parts of the metal-free dyestufi obtained according to Example 1 are stirred with 35 parts of dimethylformamide, 9 parts of 18% copper sulfate solution are added and it is stirred at room temperature for 12 hours. The separation of the copper complex is completed by the addition of 50 parts of water. The dyesruff is filtered oil with suction and dried, and in this form it consists of a dark powder which dyes synthetic superpolyamide fibres to greenish blue shades.

When a solution of 3.1 parts of crystalline nickel sulfate in 10 parts of water is employed in place of the copper sulfate solution, the resultant dyestufi dyes synthetic superpolyamide fibres to bluish violet shades.

EXAMPLE 4 has the formula N t C EXAMPLE An ammoniacal cobaltic salt solution is prepared from 3 parts of crystalline cobalt sulfate by analogy with Example 2 and this is added at 80-90 C. to a mixture of 8.4 parts of the dyestuif prepared according to Example 4, 100 parts of formamide and 15 parts of 40% sodium hydroxide solution. The mixture is heated at 8090 C. for 30 minutes and after cooling it is diluted with 500 parts of water. The resultant cobalt complex is filtered off with suction and washed with water. When dried, it consists of a dark powder.

1 part of the dry dyestuff is dispersed in 1000 arts of softened water with the aid of one part of a naphthalene-sulphonic acid/formaldehyde condensation product and 1 part of a levelling agent based on alkylphenyl-polyglycol other is added. parts of synthetic superpolyamide yam are added at 50 C. and the temperature is increased to about 100 C. Dyeing is continued at this temperature for one hour. After rinsing, a strongly bluish green dyeing is obtained, which is characterized by good fastness to light, Washing, perspiration and sea Water.

EXAMPLE 6 3.1 parts of the monoazo dyestufl 4-nitro-2-aminophenol 4,5-diphenylimidazole in a mixture of 50 parts of formamide and 50 parts of dimethylformamide are heated at 130 C. under reflux for 8 hours with 1.3 parts of crystalline chromic chloride, whilst stirring. After it has cooled, the reaction mixture is poured into 500 parts of water and adjusted to be acidic to Congo red by the addition of hydrochloric acid. When dried, the chromium complex consists of a dark powder which dyes synthetic superpolyamide fibers from a neutral or organic acid liqnor to green shades with good fastness to washing, perspiration and sea water.

Dyestuffs with similar properties are obtained when the dyestufi in this example is replaced by monoazo dyestuffs from the diazo and coupling components specified in the or cobalt complex compounds:

Color shade of complex on synthetic Coupling Type of superpoly- Diazo component component complex amide fibers 5nitro-2-amino-1- 4,5-diphenyl- Go Green.

hydroxybenzene. imidazole. 2-amino-phenol-4- ..---d0 O0 Bluish green.

sulfonic aciddirnethyl-amide 4-ehloro-2-amino-1- do C0 D0.

hydroxybenzene. 2-amino-phenol-5- -do C0 D0.

sulionic acid dimethyl amide 6-nitro-2-amino4e -.-do Go Do.

aeetylamine-lhydroxybenzene.

Dodo Cr Do. 5-nitro-3-amino'2- do C0 D0.

hydroxy-l-methylbenzene.

D0 do Cr Green. 4-chloro-6-nitro-2- .do Go Bluish green.

amino-l-hydroxybenzene.

Do do Or Do. 1-Ohl01'0-5-Illtr0? do C o D o.

amino-l-hydroxybenzene.

Do do Cr Do. echloro-4-nitr0-2- do Go Green.

amino-l-hydroxybenzene.

Do do Or Do. 4,6-dinitro-2-amino1- do Go Do.

hydroxybenzene.

Do do Or Do. 4,6-dichloro2-aJnino-1- d0 Do.

hydroxybenzene.

When a mixture of 4.2 parts of the monoazo dyestufi 4-nitro-2-amino 1 hydroxybenzene 4,5-diphenylimidazole and 4.2 parts of the monoazo dyestufr 5-nitro-2- amino-l-hydroxybenzene- 4,5-diphenylimidazole is used to replace the dyestuff employed during the cobalting operation of Example 5 during that operation, a mixed cobalt complex dyestuff is obtained which also dyes synthetic superpolyamide fibers to green shades.

When a mixture of 4.6 parts of the monoazo dyestuif 2-aminophenol-4-sulfonic acid amide 4,5-diphenylimidazole and 4.4 parts of the monoazo dyestuff Z-aminophenol-4-sulfonic acid amide 1-phenyl-3-methy1-S-pyrazolone is employed, the dyestuff which is obtained dyes natural and synthetic superpolyamide fibers to yellowish olive shades with good fastness to light and wetting.

Dyestuffs with similar properties are obtained by mixed cobalting of the monoazo dyestufis I and II specified in the following table:

Color shade on superpoly- I II amide fibers 4-nitro-2-amino-l-hydroxy- 5-nitro-2-amino-1-hydroxy- Green.

henzene 4,5-d.iohenylbenzene 4,5-diphenylazole. inn'dazole.

Do--- 4-chloro-2-amin0-1-hydroxy- Do. 1

benzene 4,5 diphenylimidazole.

Do-.. 2-aminophenol-5-sulionic Do.

acid amide 4,5diphenylimidazole.

Do 2-aminophenol-4-su1ionic Olive green.

acid amideacetoacetic acid anilide.

Do 2-a1m'nopheno1-4-Sulf0ni0 Olive.

acid amide- 1-phenyl-3- methylpyrazolone- (5) Do 2-aminophenol-4-sulionic Violet.

acid aniide 2-hydroxynaphthalene.

5-nitro-2-amino-l-hydrox1l- 2-arninophenol-4-su1fonic Green.

benzene 4,5-diphenyl acid amide 4,5-dipheny1- imidazole. imidazole. Do 4-chloro-2-arnino-1-hydroxy- Do.

benzene 4,5-diphenylimidazole.

Do Z-aminophenolA-sulfumc Olive.

acid amide-meetoacetic acid anilide.

Do 2-ami110phenOl-4rSt1lf0m0 Yellowish acid amide 1-pheny1-3- olive. methyl-5-pyrazolone.

Do 2-aminophenol-4-sulfonic Violet.

acid amide 2-hydroxy' naphthalene.

2-amino-phenol-4-sulfomc 4-ehloro-2-amino-l-hydroxy- Green.

acid amide- 4, fi-diphenbenzene 4,5-diphenylylimidaloleimidazole.

Do L -amino henol-tsulionig Olive green.

acid amideacetoacet1c acid anilide.

Do 2-aminophenol-4-S111IODi0 Yellowish acid amide- 1-phenyl-3- olive. methyl-5-pyrazolone.

2-aminophenol-4-sulfonic 2-aminophenol-4'sulphon1c Violet.

acid acid amide 2-hydroxyphenylimidazole. naphthalene. -chloroZ-amino-l-hydroxy 1 Do.

benzene-4,5-diphenylimidazole.

Do Z-aminophenol-QSUJIOHH} Olive green.

acid amideacetoacetm acid anilide.

Do 2-aminophen0l-4-Sl1lf0mc Olive.

acid amidel-phenyl-3- methyl-fi-pyrazolone.

4-nit y m y- 4-nitro-2-amino-l-hydrqxy- Green.

bQIIZBHHfi-diPhBHYL benzene-S-sulfomc acid imidazole. 4,5-diphenyl imidazole.

Do 4-nitro-2-amino-1-hydroxy Bluish benzene naphtl 1y1- ireen. amine (2)-sulfon1c acid-(5) Do 4-nitro-2-amin0-1-hyd IO Y Ohve.

benzene acetoaeetic acid anilide.

Do 4-nitro-2-amino-1-hyd Y- Do.

benezene 1-phenyl-3- methylpyrazolone- (5) Do 4-nitro-2-a.min0-1-hyd10XY- Black.

benezne 2-hydroxynaphthalene.

Do, do Dark blue.

am op u 4-nitr0-2-amm ydrqxv- Bluish acid amide 4,5-dibenzeneG-suliomc ac1d green. phenyl-imidazole. 4, 5-diphenyl imidazole.

Do 4-mtro-2-emino-1-hydroxy- Khaki.

benzeneacetoacetic acid anilide. V

Do 4-nitro-2-am n0-1-hydrOXy- Do.

benzene- 1-phenyl-3- methylpyrazolone- (5) Do .;.-*4-nitro-2-amino-1-hydroxy- Black.

benzene 2-hyrdoxynaphthalene.

Do Z-aminophenol-S-SulfomG. Blue.

acid-dimethylamide 2- hydroxynaphthalene.

Do 3-amino-4-hydroXy-l- Do.

- methyl benzene- 2- hydroxynaphthalene.

Do 5-nitro-2-amino-l-hydroxy- Do.

benzene- 2-hydroxynaphthalene.

Do 5-m'tro-3-amino-4-hydroxy- Do.

. 1-methylbenzene 2- hydroxynapththalene. Do 4-nitro-2-amino-l-hydroxy- Blue green.

. benzene- 2-hvdroxy&

acetylaminonaphthalene Do 6-nitro-2-amind4-acetyl- Do.

. amino-l-hydroxybenzene 2-hydroxy-8-n1ethy1- sulionylaminonaphthaene.

Color shade on Super polyamide fibers Blue.

2-aminophenol-5-sulfonic acid dimethylamide 3- hydIoxy-diphenylamine. 4-nitro-2-amino-l-hydroxybenzene-6'sulfonic acid 4, S-diphenylimidazole. 4-nitro-2-amino-l-hydroxybenagne acetoacetic acid 1 e. 4nitro-2-amino-1-hydroxybenzene-+1-phenyl-3- rnethylpyrazolone- (5). 4-nitro-2-amino-l-hydroxybenzene- 2-hydroxynaphthalene. 5-nitro-2-amino-1-hydroxybenzene 2-hydroxynaphthalene.

4-chloro-2-a1nino-l-hy- Green.

droxybenzene 4,5- diphenylimidazole.

' Olive.

Black.

Dark blue.

EXAMPLE 8 8.1 parts of this dyestufi in 100 parts of formamide and 15 parts of 40% sodium hydroxide solution are metallized at about C. with an amoniacal solution of cobaltic salt from 3 parts of crystalline cobaltic sulfate (by analogy with Example 5) and the resultant dyestufi-cobalt complex is precipitated by the addition of parts of Water. It dyes synthetic superpolyamide fibers and wool to clear Bordeaux shades.

5.4 parts of the metal-free dyestutt in this example are heated in 100 parts of formamide at 80 C. for 4 hours with 2.2 parts of crystalline chromic chloride, whilst stirring. After. it has cooled, the solution is diluted with 400 parts of Water and the dycstuff-chromium complex is precipitated by the addition of 40 parts of sodium chloride. It dyes synthetic superpolyamide fibers and wool to clear violet shades.

If replacing the dyestuft of this example by monoazo dyestufi from the diazo and couplingcomponents listed in the following table and converting them into the chromiurn or cobalt complex compounds, dyestuffs and similar properties are obtained.

4.05 parts of the monoazo dyestutf 2-aminobenzoic acid 4,5-diphenylimidazole and 4.55 parts of the monoazo dyestufi 2-aminophenol-4-sulfonic acid amide 4,5-diphenylimidazole are heated to 80 C. with parts of water and 15 parts of 40% sodium hydroxide solution.

'9 At this temperature, an ammoniacal solution of 'cobaltic salt is added with stirring in analogous manner to Example 5. After completion of the metallization the dyestufl is precipitated at pH 9 with dilute acetic acid. It dyes superpolyamide fibers blue shades.

Dyestufis with similar properties are obtained by mixed cobalting of the monoazo dyestufis obtained by coupling the diazo and coupler corresponding to the amine/coupler pairs in I and II specified in the following table.

Color shade on superpoly- I II amide Z-aminobenzoic acid 4-nitro-2-amino-1-hydr0xy Red brown.

-4,5-diphenyli midazole. benzeneacetoacetie acid anilide. Do- 2-aminophenol-4-sul1onic Do.

acid amide l-phenyl-fi-h methyl-pyrazolone 2-amino4-acety1amino- 2-arninophenol-4-sullonic Blue.

benzoic acid 4,5-diacid amide 4,5diphenphenylimidazole. phenylimidazole.

Do- 4-nitro-2-amino-1-hydroxy- Dark brown. benzeneaacetonetic acid anilide. 2-amino-5-acety1aminodo Do.

benzoic acid 4,5-diphenylimidazole.

Do 4-nitro-2-amino-1-hydroxy- Do.

benzene+ 1-phenyl-& methyl-pyrazolone-(5). Do 2-aminophen0l-4-sulfonic Blue.

acid amide 4,5-diphenylimidazole.

We claim:

1. A metal complex of one atom of (l) a metal having an atomic number from 24 to 29 and one or two molecules of (2) an azo dyestufi of the formula:

in which A is a member selected from the group consisting of phenylene, naphthylene, and phenylene or naphthylene substituted with members selected from the group consisting of lower alkyl, lower alkoxy, Cl, Br, nitro, acetyl, acetylamino, sulfo, sulfonamide, lower alkyl sulfonamide, di-lower alkyl sulfonamide,,hydroethylsulfonamide, sulfonic acid anilide, and lower alkyl sulfonyl; X is a substituent in the o-position to the azo group capable of being complexed with a metal and is selected from the group consisting of hydroxyl, carboxyl, and chloro; and R and R taken separately, are members selected from the group consisting of hydrogen, lower alkyl, phenyl, chlorophenyl, lower alkoxyphenyl, V di-lower alkyl aminophenyl, hydroxyphenyl, bromophenyl, and furyl groups, and, taken together, are the member of a cyclohexane ring.

2. A dyestufi of claim 1 wherein the complex bound metal is selected from the class consisting of cobalt and chromium, one atom of metal being in complex union with substantially two molecules of said azo dyestuff.

3. An azo dyestulf comprising the complex of one atom of a metal selected from the group consisting of chromium and cobalt and substantially two molecules of complex-forming azo dyestuffs selected from the group consisting of compounds having the formula:

in which at least one of said compounds has the formula (1) and in which A is a member selected from the group consisting of phenylene, naphthylene, and phenylene o1 naphthylene substituted with members selected from the group consisting of lower alkyl, Cl, Br, acetyl, nitro, acetylamino, sulfo, sulfonamide, lower alkyl sulfonamide, di-lower alkyl sulfonamide, hydroxyethylsulfonamide, sulfonic acid anilide, and lower alkyl sulfonyl; B is a residue selected from the group consisting of enolic and phenolic compounds containing the OH group in adjacent position to the azo bridge; X is a substituent in the o-position to the azo group capable of being complexed with metal and is selected from the group consisting of hydroxyl, carboxyl, and chloro; R and R taken separately, are members selected from the group consisting of hydrogen, lower' alkyl, phenyl, ehlorophenyl, lower alkoxyphenyl, di-lower alkyl aminophenyl, hydroxyphenyl, bromophenyl, and furyl groups, and, taken together, are the members of a cyclohexane ring; R is a member selected from the group consisting of sulfonamide, lower alkyl substituted sulfonamide, di-lower alkyl substituted sulfonamide, nitro, hydrogen, and chloro; R is phenyl; and R is a member selected from the group consisting of hydrogen, lower alkyl -CONH and lower alkyl SO NH.

4. The 2:1 cobalt complex of a dyestufi of the formula wherein R is a member selected from the class consisting of sulfonamide, loweralkyl substituted sulfonamide, dilower alkyl substituted sulfonamide, hydroxyethylsulfonamide, nitro, chloro, and hydrogen.

5. The 2:1 cobalt complex of a dyestutf of the formula wherein R is a member selected from the class consisting otlower alkoxy, acetylamino, lower alkyl sulfonylamino, and hydrogen. I 6. The mixed 2:1 cobalt complex of the dyestufis of the formulae wherein R stands for a member selected from the class consisting of sulfon'amide, lower alkyl substituted sulfon- 11 amide, di-lower alkyl substituted sulfonamide, hydroxyethylsulfonamide, nitro, hydrogen, and chloro, and R stands for phenyl.

7. The mixed 2:1 cobalt complex of the dyestuffs of the formulae H OH lac-0,11, I

a C-CeHs V CE v N=N CH Q I and wherein R is a member selected from the class consisting of sulfonamide, lower alkyl substituted sulfonamide, di lower alkyl substituted sulfonamide, hydroxyethylsulfonamide, nitro, hydrogen, and choloro, and R is phenyl.

8. The mixed 2:1 cobalt complex of the dyestuffs of the formulae 7 wherein R is a member selected from the class consisting of sulfonamide, lower alkyl substituted sulfonamide, dilower alkyl substituted sulfonamide, hydroxyethylsulfonamide, hydrogen, nitro, and chloro, and R is a member selected from the class consisting of hydrogen, acetylamino, and lower alkyl sulfonylarnino.

9. The mixed 2:1 cobalt complex of the dyestuffs of the formulae and 12 11. The 2: 1 cobalt complex of the dyestutf of the formula 12. The 2:1 cobalt complex ofthe dyestulf of the formula V NO: v 13. The 2:1 cobalt complex of the dyestutf of the formula f a I CCgH5 N=N'-c N-c-cm,

14. The 2:1 cobalt complex of the dyestuff of the 15. The mixed 2 :1 cobalt complex of the dyestuffs or the formulae 16. The mixed 2:1 cobalt complex of the dyestuffs of the formulae I v 17. The mixed 2:1 cobalt complex of the dyestuffs of the formulae 18 The mixed 2:1 cobalt complex of the dyestufis of and the formulae B; N- 20. The mixed 2:1 cobalt complex of the dyestufis of the formulae H OH OH E? 19. The mixed 2:1 cobalt complex of the dyestuffs of the formulae References Cited OH 0 UNITED STATES PATENTS /NCC|H.-. 3,102,879 9/1963 Bauman et a]. 260-157 N=NO CHARLES B. PARKER, Primary Examiner N-C-(hH;

N0: 0. T. WARREN, Assistant Examiner g g UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3I468I 871 Dated eptember 23 1969 Inventr(s) KLAUS LEVERENZ and ALOIS GOTTSCHLICH It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 40 that portion of the formula reading N=-N- should read N=N- Column 2 line 5, "heteroatoms. should read -hetero atoms. Column 3 line 17, "-7-aminobenzene" should read -laminobenzene Column 3, line 22 3aminobenzene" should read 2aminobenzene Column 3 line 44 "4 ,5- bis- (4" should read -4 ,5-bis (4 Column 3 line 75 "of synthetic" should read -or synthetic-.

Column 7 line 2 of Table under headingI"4 ,5diohenyl" should read 4 ,5-diphenyl- Column 7, line 45 "bluish freen" should read, -bluish green; Column 7 line 50 "benezene"should read, benzene-; Column 7 line 52 under heading II Table, "benezne" should read benzene-; Column 7 line 60 under heading II of the Table, "hyrdoxy" should read hydroxy- Column 7, line 64 under heading II of the Table, "methyl benzene" should read -methylbenzene.

Column 8, line 55 "dyestuffs and" should read --dyestuffs with.

Column 9 line 53 "the member" should read -the members-; Column 9, line 44 "hydroethylsul-" should read hydroxyethylsul.

Column 11 line 10, that portion of the formula reading I I l N- N-C should read N-C Page Two Column 11, line 23, "choloro, should read --chloro,-;

Column 11, line 30 that portion of the formula reading H -c-c n *v-c-c n 5 should read c 6 5 \w-c n n-oc n Column 11, line 50, that portion of the formula reading Column 12 line 5, that portion of the formula reading Column 12 Mum-w" line 50, that portion of the formula readinq should read N-C WM '1 9 mm 

